1. Field of the Invention
The present invention relates to a hydraulic clutch control device of a vehicle power unit.
2. Description of Related Art
Japanese Patent Application Publication No. 2010-255840 discloses a structure including an oil pressure control valve to control an oil pressure of a hydraulic clutch inserted in a power transmission system of a power unit; and an actuator to drive the oil pressure control valve, the oil pressure control valve and the actuator being housed in a housing chamber filled with a hydraulic oil so as to prevent operating noise of the oil pressure control valve and the actuator from leaking to the outside.
In the structure disclosed in Japanese Patent Application Publication No. 2010-255840, the housing chamber is formed to be quite larger than the whole of the oil pressure control valve and the actuator, and the whole of the oil pressure control valve and the actuator is immersed deep in the hydraulic oil. This prevents the oil pressure control valve from being exposed above the oil level even when part of the housing chamber is not filled with the hydraulic oil, which flows out more than necessary from an oil return hole communicating with an upper portion of the housing chamber, because the vehicle body inclines frontward or rearward when the vehicle climbs or descends a slope while travelling. However, in order to provide such a large housing chamber in the engine main body, a relatively large space needs to be secured in the engine main body. This may not only restrict the disposing position but may also lead to increase in size of the engine main body.